Best TLD for Startups: .com vs .ai vs .io vs .co

You've been staring at a domain search bar for an hour. Every .com you try is taken. So you start wondering: is .ai legit? What about .io? Would .co confuse people?

Your TLD matters—but not for the reasons most people think. Google doesn't care which extension you use. Your customers might.

Google Treats All Major TLDs Equally

Let's kill the biggest myth first.

Google doesn't prefer .com over other extensions. All generic top-level domains are treated equally in rankings. Google has stated that TLD choice has no direct SEO impact—content quality and backlinks matter far more.

The indirect effect is real, though. If people trust .com more and click it more often in search results, that higher click-through rate helps performance. The extension isn't a ranking signal—but the human response to it can be.

Pick the TLD that fits your brand and audience. Then stop worrying about it.

.com: The Default (For Good Reason)

Cost: ~$10–20/year | Availability: Low for short/common names

According to W3Techs, .com powers roughly 44% of all websites globally—more than any other TLD by a wide margin. It's what autocomplete suggests. It's what email clients trust by default.

Y Combinator's Winter 2024 batch: 132 out of 248 companies (53%) chose .com. Even in a batch where most startups were AI-focused, more than half still reached for .com.

Why founders choose it:

• Universal recognition and trust
• Better email deliverability, zero compatibility issues
• No explanation needed—ever
• Strongest choice for international expansion

The real problem: Availability. Good short .com names are nearly impossible to get. You're either paying aftermarket prices ($1K to $1M+) or compromising on the name itself.

Those costs keep climbing. Verisign's agreement with ICANN allows .com wholesale pricing to increase by up to 7% annually in the final four years of each six-year contract period, with the next increase window opening in 2026.

Best for: Startups targeting broad consumer appeal, international markets, or trust-dependent industries—fintech, health, insurance. If you can get a strong name on .com, take it.

.ai: The Startup Signal

Cost: ~$70–100/year (2-year minimum) | Availability: Moderate

The .ai extension has grown rapidly since the AI boom began. Registrations surged from around 60,000 in 2022 to over 550,000 by early 2025. The extension technically belongs to Anguilla, but everyone reads it as "artificial intelligence."

In YC's Winter 2024 batch, 58 out of 248 companies (23%) chose .ai. By Q1 2025, roughly 28% of startups were choosing .ai as their domain extension.

Google treats .ai as a generic top-level domain—no geographic restriction to Anguilla. No SEO penalty.

Why founders choose it:

• Instant industry signaling for AI and tech companies
• Better short-name availability than .com
• Growing adoption creates its own legitimacy
• Over 90% renewal rate suggests registrants find the value worth the cost

What to watch out for:

The price is steep. The two-year minimum costs at least $140 upfront, and starting March 2026, the wholesale cost increased by $10/year, raising the minimum two-year registration to $160.

Worth noting: many established AI companies haven't adopted .ai. DeepMind stays on .com. Meta redirected facebook.ai to ai.meta.com. The biggest players often keep .com as primary.

Best for: AI startups, ML companies, developer tools—any company where "we do AI" is the first thing you want people to understand. If you're building a bakery, skip it.

.io: The Developer Favorite (With a Caveat)

Cost: ~$25–45/year | Availability: Moderate

Technically the ccTLD for the British Indian Ocean Territory, but tech companies adopted it for the I/O (input/output) association. For a decade, .io has been the go-to for developer tools, open-source projects, and B2B SaaS. GitHub Pages uses it. Socket.io, itch.io, and hundreds of dev tools run on it.

Google treats .io as a generic extension—no geographic restrictions, no SEO concerns.

The elephant in the room:

In October 2024, the UK announced it would cede sovereignty of the British Indian Ocean Territory to Mauritius. A treaty was signed in May 2025. Since .io is technically this territory's country code, its long-term future got complicated.

Should you panic? Probably not. If the ISO 3166-1 code were removed, ICANN's retirement policy would apply—a phase-out period of at least five years. And a sovereignty change doesn't guarantee a change to .io's status.

But "probably fine" and "definitely fine" are different things. The risk is real. Have a backup plan.

Best for: Developer tools, open-source projects, SaaS with technical audiences. If your users already live in the .io ecosystem—GitHub, npm, indie hacking communities—it carries credibility. Consider owning the .com as a backup.

.co: The Affordable Alternative

Cost: ~$10–30/year | Availability: Good

Colombia's ccTLD, actively promoted as a global business domain. Some startups launch on .co and transition to .com later as they scale. The key advantage: availability and low cost.

The problem nobody talks about:

Users habitually type ".com" and land on the wrong site. The verbal similarity between ".co" and ".com" creates constant spelling mix-ups. Every time you say your domain on a podcast, you'll be saying "dot-C-O, not dot-com." That friction compounds.

Best for: Bootstrapped founders who need something now, plan to upgrade to .com later, and can tolerate occasional misdirected visitors. Works better with very distinctive brand names where confusion is less likely.

.app and .net: The Supporting Cast

.app (~$15–20/year): Google's own TLD. Requires HTTPS by default. Works for mobile-first companies, but the positioning feels limiting if your product expands beyond "an app."

.net (~$10–15/year): The original .com alternative. In 2026, it reads as "the .com was taken." Works fine technically, carries a perception penalty with non-technical audiences.

Neither is bad—but neither sends a signal the way .ai or .io does. Functional, not strategic.

Quick Comparison

TLD	Annual Cost	Availability	SEO Impact	Best Signal	Biggest Risk
.com	$10–20	Low	Neutral (highest trust)	"Established business"	Name you want is taken
.ai	$70–100	Moderate	Neutral (treated as gTLD)	"AI / tech company"	High cost, 2-year minimum
.io	$25–45	Moderate	Neutral (treated as gTLD)	"Developer tool / tech"	Geopolitical uncertainty
.co	$10–30	Good	Neutral	"Modern startup"	Confused with .com
.app	$15–20	Good	Neutral	"Mobile-first product"	Narrow positioning
.net	$10–15	Good	Neutral	None, really	Feels like a backup

How to Actually Decide

1. Get the name right first.

The name matters 10x more than the extension. A great name on .ai beats a mediocre name on .com every time. Aim for 5–6 characters, two syllables, strong opening consonant, easy to spell from hearing it. The extension is a tiebreaker, not the main event.

2. Match your audience.

Selling to developers? .io is native. Building AI tools? .ai is expected. Selling to consumers who aren't tech-savvy? .com removes all friction. Your audience's expectations should drive this, not your preferences.

3. Check what's actually available.

The theoretical best extension means nothing if your name isn't available on it. A name you love on .ai beats a name you settled for on .com. Check availability across multiple TLDs before you get attached to one extension.

Stop Checking Domains One by One

You think of a name, check the .com—taken. Try .ai—taken. Try .io—available but you're unsure. Repeat for the next name. And the next.

That loop is what we built Zeer to break. Describe your business idea, get name suggestions with real-time domain availability across .com, .ai, .io, .co, .app, and .net—checked live via RDAP, not cached. Every name includes a ZeerScore rating so you know if it's actually good, not just available.

The best TLD for your startup is the one attached to a great name that's available right now. Go find it.

FAQ

Does my domain extension affect Google rankings?

No. Google treats all generic domains (.com, .io, .ai, .tech) equally in search rankings. Extensions can indirectly affect SEO through click-through rates—users trust familiar extensions like .com more—but the extension itself isn't a ranking signal.

Is .ai a good domain for non-AI companies?

It can work, but you'd be swimming against the signal. Users read .ai as "AI-related." If your product has nothing to do with AI, that mismatch creates confusion.

Will .io domains go away?

Not anytime soon. Even if .io were eventually retired, IANA would announce that well in advance—most likely with a phase-out period of at least five years. But the uncertainty is real, and registering a backup domain is smart.

Should I buy multiple TLDs for brand protection?

At minimum, grab the .com of your brand name if it's available, even if you run your site on a different extension. It prevents competitors or squatters from confusing your customers. Beyond that, three or four extensions is plenty for most startups.

What's more important—the name or the extension?

The name. Always. A memorable, pronounceable, 5–6 character name on .io will outperform a forgettable name on .com every time. Get the name right first, then figure out the TLD.